Science and medicine

Joseph Jackson Lister's microscope, London, England, 1826

Microscopes

The job of the scientist

Scientists at the frontiers of medical research observe nature with the twin aims of uncovering facts and formulating laws. This admirable work inevitably involves making very detailed observations of the human body and its diseases.

The use of dissection from the 2nd century CE

In the 2nd century CE, the Greek physician Galen, one of the pioneers of medical science, used living pigs to demonstrate that the brain controlled the body. Later, the Renaissance anatomist Andreas Vesalius urged physicians to conduct dissections and make their own observations rather than trusting to descriptions of the body that had been handed down by ancient and far from reliable medical authorities (such as Galen).

Experiments through time that led to the discovery of blood circulation

Doctors also conducted experiments. The Persian scholar Ibn Sina developed rules for testing the effectiveness of drugs on hospital patients in the late 900s. In the 1200s Ibn Al-Nafis discovered the pulmonary circulation of the blood (between the heart and the lungs). This discovery remained largely unknown in Europe until the 1600s, when the English physician William Harvey devised experiments to prove the circulation of blood.

What counts as science?

Medical doctors also borrowed concepts from other scientific disciplines, such as physics and chemistry, to explain sickness and health, although opinions on what counts as science have changed over time. Outside of the pages of some tabloid newspapers, astrology is no longer considered a science. Yet it is based on systematic observations of the heavens, and it formulates laws and principles. For centuries physicians in Christian Europe, the Islamic world and in China used it in their medical practice.

Experimenting and measuring: the Enlightenment of the 1700s

In the 1700s, philosophers of the Enlightenment began to advocate science as a motor of progress. Contemporaries celebrated the scientific genius of people such as physicist Isaac Newton. Hermann Boerhaave and other physicians attempted to develop a form of ‘Newtonian medicine’ based on experiment and measurement. The claim to scientific objectivity provided physicians with the ammunition they needed to claim superiority over other healers, such as midwives and barber-surgeons - an argument which ultimately helped them dominate the lucrative medical marketplace.

Professional careers as medical scientists in the 1800s

But many features of modern science didn’t become standard elements of scientific practice until the 1800s. Clinical research, laboratories, government funding, scientific journals and professional associations all date from this period. When these elements were introduced, men (and later women too) could pursue professional careers as medical scientists.

Observing patients in hospitals in 1800

Around 1800, French physicians began to use hospitals for clinical research. Hospitals provided opportunities to observe large numbers of patients. If a patient died, the body could be dissected to find links between external symptoms and pathological causes inside the body. This approach soon spread throughout Western medicine.

The introduction of laboratories in the 1800s

With the introduction of laboratories in the 1800s, experimentation became an important part of medical research. The German chemist Justus von Liebig installed a chemical laboratory at the university where he taught. His research and that of his students was very successful, and soon other universities began to build their own laboratories. Scientists used their experiments and measurements to argue that the human body could be understood in the same way as any other object. In 1842, Liebig showed that chemical laws operate on living bodies and inanimate matter alike. Hermann von Helmholtz did the same in 1847 for physical laws.

Technological advances in the 1800s

In the 1800s, research institutes provided the newly minted professional scientists with space, equipment and money to conduct experiments. Technological advances greatly improved scientific instruments such as the microscope and the thermometer and led to the invention of new instruments such as the ophthalmoscope for looking inside the eye, and the sphygmograph for measuring blood pressure.

Improved instruments contributed to new understandings of the body. The microscope, for instance, led to the discovery of the cell as the fundamental building block of the human body. It also contributed to the development of the germ theory of disease by Louis Pasteur, Robert Koch and others since 1861.

The role of chance in medical discoveries

But chance continued to play a role in medical discoveries. In 1847 James Simpson began a revolution in the practice of surgery when, while experimenting at home with some friends, he discovered that chloroform could serve as a very effective anaesthetic. In 1928 the Scottish bacteriologist Alexander Fleming accidentally discovered that penicillin killed bacteria - a discovery that ultimately saved many lives in the Second World War and led to the development of many new antibiotics.

New scientific principles and new understanding after 1900

After 1900 the combined forces of different scientific disciplines and techniques led to new understandings of the body. In their 1953 discovery of the structure of DNA, Francis Crick and James Watson were able to draw on their own previous work in biology and physics as well as on the results of X-ray studies by Rosalind Franklin and Maurice Wilkins.

New problems for science

Today, medical research uses vast resources to develop new drugs and techniques to combat diseases. Science has helped us to create solutions to long-standing medical problems, but it also raises new questions. Some are of a practical nature: the frequent use of antibiotics, for instance, has caused the emergence of resistant disease strains, the so-called 'superbugs'.

Ethical problems associated with new solutions

Other possible solutions pose ethical problems: should scientists be allowed to experiment on humans, embryos and animals? And should we use science to keep very ill people alive under any circumstances - no matter how clever the science?